Encapsulation controls moisture; insulation controls heat. If the crawl space is damp, encapsulate first — insulation installed into a humid space gets wet and stops working. If the space is genuinely dry and the floor above is cold, insulation alone may be all you need.
Different problems, different symptoms
Musty smell, cupping floors, visible growth on framing and high humidity readings are moisture symptoms, and insulation does nothing for any of them. Cold floors in winter and high heating bills are thermal symptoms, and a liner does very little for those.
Most Cape Fear crawl spaces present with the first set, which is why encapsulation is usually the first purchase here.
Why order matters financially
Insulation installed in a humid crawl space absorbs moisture, loses R-value and eventually has to be removed. Paying for it twice is the common outcome of doing it first.
Encapsulation also changes which insulation is correct: sealing the space moves the thermal boundary from the subfloor to the perimeter walls, so subfloor batts installed beforehand become the wrong product in the wrong place.
The bottom line
Moisture first, heat second. On a Wilmington crawl space that almost always means encapsulate, then insulate the walls — not the other way round.
For a number against your own crawl space, use the cost estimator, or call (910) 886-2018 and we will come and measure it.